The adjustment to the basis (reference rate) used for calculation of the interest rate on borrowings. [Refer: Borrowings]

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The interest rate on borrowings. [Refer: Borrowings]

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The basis (reference rate) used for calculation of the interest rate on borrowings. [Refer: Borrowings]

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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

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The amount of a hedging instrument, recognised as a liability. [Refer: Hedging instruments [domain]]

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The amount of income tax relating to amounts recognised in other comprehensive income. [Refer: Other comprehensive income]

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Effective interest rate percentage.

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Fixed interest rate percentage.

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Hedging activities and derivatives - Additional Information (Detail) € in Millions, ₨ in Millions, ¥ in Millions, ¥ in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2026 INR (₨)	Mar. 31, 2025 INR (₨)	Mar. 31, 2024 INR (₨)	Mar. 31, 2026 USD ($)	Mar. 31, 2026 JPY (¥)	Mar. 31, 2026 EUR (€)	Mar. 31, 2026 CNY (¥)	Mar. 31, 2025 USD ($)	Mar. 31, 2025 JPY (¥)	Mar. 31, 2025 EUR (€)	Mar. 31, 2025 CNY (¥)
Disclosure of detailed information about hedges [line items]
Gain (loss) on hedge ineffectiveness, recognised in other comprehensive income \| ₨	₨ 1,668	₨ 287	₨ (378)
Deferred tax liability (Asset) on cash flow edges, recognised in other comprehensive income \| ₨	₨ 283	₨ 91	₨ (82)
Fair Value Hedges Reserve
Disclosure of detailed information about hedges [line items]
Fixed interest rate percentage	8.05%
Effective interest rate percentage	2.47%
Cash Flow Hedge Reserve \| COS \| Senior Secured Notes Included In Short Term Borrowings
Disclosure of detailed information about hedges [line items]
Hedging instruments, liability				$ 500				$ 851
Cash Flow Hedge Reserve \| POS \| Senior Secured Notes Included In Short Term Borrowings
Disclosure of detailed information about hedges [line items]
Hedging instruments, liability				0				311
Cash Flow Hedge Reserve \| CCS \| Senior Secured Notes Included In Short Term Borrowings
Disclosure of detailed information about hedges [line items]
Hedging instruments, liability				1,328	¥ 31,924	€ 0		1,892	¥ 11,845	€ 0
Cash Flow Hedge Reserve \| Foreign Currency Call Options \| Senior Secured Notes Included In Short Term Borrowings
Disclosure of detailed information about hedges [line items]
Hedging instruments, liability				225				0
Cash Flow Hedge Reserve \| Foreign Currency Forwards \| Senior Secured Notes Included In Short Term Borrowings
Disclosure of detailed information about hedges [line items]
Hedging instruments, liability				659		€ 0	¥ 55	167		€ 2	¥ 2,512
Cash Flow Hedge Reserve \| Call Spread \| Senior Secured Notes Included In Short Term Borrowings
Disclosure of detailed information about hedges [line items]
Hedging instruments, liability				$ 400			¥ 712	$ 450			¥ 202
Loan \| Floating interest rate \| Receiving interest [member]
Disclosure of detailed information about hedges [line items]
Borrowings, interest rate basis	3 months SOFR
Loan \| Floating interest rate \| SOFR \| Receiving interest [member]
Disclosure of detailed information about hedges [line items]
Borrowings, plus adjustment to interest rate basis				2.00%	2.00%	2.00%	2.00%
Loan \| Floating interest rate \| TONA \| Receiving interest [member]
Disclosure of detailed information about hedges [line items]
Borrowings, plus adjustment to interest rate basis				1.40%	1.40%	1.40%	1.40%
Bottom of range [member] \| INR \| Senior Secured Notes Included In Short Term Borrowings
Disclosure of detailed information about hedges [line items]
Borrowings, interest rate				4.71%	4.71%	4.71%	4.71%
Bottom of range [member] \| US \| Senior Secured Notes Included In Short Term Borrowings
Disclosure of detailed information about hedges [line items]
Borrowings, interest rate				4.50%	4.50%	4.50%	4.50%
Bottom of range [member] \| Loan \| Paying interest [member]
Disclosure of detailed information about hedges [line items]
Borrowings, interest rate				6.33%	6.33%	6.33%	6.33%
Bottom of range [member] \| Loan \| Fixed interest rate
Disclosure of detailed information about hedges [line items]
Borrowings, interest rate				2.88%	2.88%	2.88%	2.88%
Top of range [member] \| INR \| Senior Secured Notes Included In Short Term Borrowings
Disclosure of detailed information about hedges [line items]
Borrowings, interest rate				10.25%	10.25%	10.25%	10.25%
Top of range [member] \| US \| Senior Secured Notes Included In Short Term Borrowings
Disclosure of detailed information about hedges [line items]
Borrowings, interest rate				7.15%	7.15%	7.15%	7.15%
Top of range [member] \| Loan \| Paying interest [member]
Disclosure of detailed information about hedges [line items]
Borrowings, interest rate				10.21%	10.21%	10.21%	10.21%
Top of range [member] \| Loan \| Fixed interest rate
Disclosure of detailed information about hedges [line items]
Borrowings, interest rate				7.00%	7.00%	7.00%	7.00%